Vortex phase diagram of rotating superfluid He3−B

Abstract

We present the first theoretical calculation of the pressure-temperature-field phase diagram for the vortex phases of rotating superfluid 3 He-B. Based on a strong-coupling extension of the Ginzburg-Landau theory that accounts for the relative stability of the bulk A and B phases of 3 He at all pressures, we report calculations for the internal structure and free energies of distinct broken-symmetry vortices in rotating superfluid 3 He-B. Theoretical results for the equilibrium vortex phase diagram in zero field and an external field of H = 284 G parallel to the rotation axis, H Ω Ω Ω, are reported, as well as the supercooling transition line, T * V (p, H). In zero field the vortex phases of 3 He-B are separated by a first-order phase transition line T V (p) that terminates on the bulk critical line T c (p) at a triple point. The low-pressure, low-temperature phase is characterized by an array of singly-quantized vortices that spontaneously breaks axial rotation symmetry, exhibits anisotropic vortex currents and an axial current anomaly (D-core phase). The high-pressure, high-temperature phase is characterized by vortices with both bulk A phase and β phase in their cores (A-core phase). We show that this phase is metastable and supercools down to a minimum temperature, T * V (p, H), below which it is globally unstable to an array of D-core vortices. For H 60 G external magnetic fields aligned along the axis of rotation increase the region of stability of the A-core phase of rotating 3 He-B, opening a window of stability down to low pressures. These results are compared with the experimentally reported phase transitions in rotating 3 He-B.

Quasiclassical free energy of superconductors: Disorder-driven first-order phase transition in superconductor/ferromagnetic-insulator bilayers

“…Even though the spin-triplet superfluity in 3 He has been studied for many years, the Eilenberger-type free-energy expression is derived only in the present paper, advancing the theory of spintriplet paired states. This tool should be particularly useful to study different competing and spatially inhomogeneous phases for the confined topological superfluids [6,44,63,64], exotic disordered phases [65,66], and vortex states, such as double-core vortices [67][68][69][70][71][72][73][74] and recently found halfquantum vortices [75,76]. We now derive Eq.…”

Quantum Elliptic Vortex in a Nematic-Spin Bose-Einstein Condensate

“…However, the dynamics are poorly understood, because of the lack knowledge about properties of wall-HQV composites. Determining these properties is important for understanding KLS-wall-HQV composites and double-core vortices in 3 He-B [41][42][43][44][45]), the Berezinskii-Kosterlitz-Thouless transition in spinor BECs [46][47][48], and even the quark-confinement problem in hadronic physics connected with the vortex-confinement problem [49][50][51][52].…”

Half-Quantum Vortices in Nematic and Chiral Phases of $^3$He

“…[1]. This strong-coupling GL formalism also accounts for the relative stability of the A and B phases of pure superfluid 3 He over the entire pressure-temperature range [12], as well as the vortex phase diagram of rotating 3 He-B [13]. Using the strong-coupling GL theory, with the addition of the impurity model for the Nafen described below, we predict the pressure-temperature phase diagram for superfluid 3 He-Nafen.…”

“…We first discuss the stabilization of the polar and polar-distorted chiral phases of superfluid 3 He infused into Nafen aerogel. Impurity Model for 3 He in Nafen -Ginzburg-Landau theory has been formulated to calculate the order parameter and thermodynamic properties of inhomogeneous phases of superfluid 3 He [2,3,12,13]. Here we develop the strongcoupling formulation of GL theory for superfluid 3 He infused into Nafen aerogels.…”

“…These terms, and the pressure-dependent material coefficients that define the strong-coupling GL functional, are discussed in detail in Ref. [13] and summarized in the Appendix. The last term in Eq.…”